31 lines
862 B
Plaintext
31 lines
862 B
Plaintext
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package GlitchFilter;
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import Cntrs::*;
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(* always_enabled="_write",always_ready="_read" *)
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module mkGlitchFilter(Integer hysteresis, bit init_value, Reg#(bit) ifc);
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Wire#(bit) in <- mkBypassWire();
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UCount cnt <- mkUCount(init_value == 0 ? 0 : hysteresis, hysteresis);
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Reg#(bit) out[2] <- mkCReg(2, init_value);
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(* no_implicit_conditions, fire_when_enabled *)
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rule incr (cnt.isLessThan(fromInteger(hysteresis)) && in == 1);
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cnt.incr(1);
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endrule
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(* no_implicit_conditions, fire_when_enabled *)
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rule decr (cnt.isGreaterThan(0) && in == 0);
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cnt.decr(1);
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endrule
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(* no_implicit_conditions, fire_when_enabled *)
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rule set_out (cnt.isEqual(0) || cnt.isEqual(fromInteger(hysteresis)));
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out[0] <= cnt.isEqual(0) ? 0 : 1;
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endrule
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method _write = in._write;
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method _read = out[1]._read;
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endmodule
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endpackage
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